Unnamed repository; edit this file 'description' to name the repository.
Support overloaded index MIR lowering
| -rw-r--r-- | crates/hir-ty/src/consteval/tests.rs | 46 | ||||
| -rw-r--r-- | crates/hir-ty/src/infer/mutability.rs | 15 | ||||
| -rw-r--r-- | crates/hir-ty/src/mir/lower/as_place.rs | 63 | ||||
| -rw-r--r-- | crates/ide-diagnostics/src/handlers/mutability_errors.rs | 48 |
4 files changed, 169 insertions, 3 deletions
diff --git a/crates/hir-ty/src/consteval/tests.rs b/crates/hir-ty/src/consteval/tests.rs index a658bfa0c9..944912b6c2 100644 --- a/crates/hir-ty/src/consteval/tests.rs +++ b/crates/hir-ty/src/consteval/tests.rs @@ -2,7 +2,8 @@ use base_db::fixture::WithFixture; use hir_def::db::DefDatabase; use crate::{ - consteval::try_const_usize, db::HirDatabase, test_db::TestDB, Const, ConstScalar, Interner, + consteval::try_const_usize, db::HirDatabase, mir::pad16, test_db::TestDB, Const, ConstScalar, + Interner, }; use super::{ @@ -30,7 +31,12 @@ fn check_number(ra_fixture: &str, answer: i128) { match &r.data(Interner).value { chalk_ir::ConstValue::Concrete(c) => match &c.interned { ConstScalar::Bytes(b, _) => { - assert_eq!(b, &answer.to_le_bytes()[0..b.len()]); + assert_eq!( + b, + &answer.to_le_bytes()[0..b.len()], + "Bytes differ. In decimal form: actual = {}, expected = {answer}", + i128::from_le_bytes(pad16(b, true)) + ); } x => panic!("Expected number but found {:?}", x), }, @@ -216,6 +222,42 @@ fn overloaded_deref_autoref() { } #[test] +fn overloaded_index() { + check_number( + r#" + //- minicore: index + struct Foo; + + impl core::ops::Index<usize> for Foo { + type Output = i32; + fn index(&self, index: usize) -> &i32 { + if index == 7 { + &700 + } else { + &1000 + } + } + } + + impl core::ops::IndexMut<usize> for Foo { + fn index_mut(&mut self, index: usize) -> &mut i32 { + if index == 7 { + &mut 7 + } else { + &mut 10 + } + } + } + + const GOAL: i32 = { + (Foo[2]) + (Foo[7]) + (*&Foo[2]) + (*&Foo[7]) + (*&mut Foo[2]) + (*&mut Foo[7]) + }; + "#, + 3417, + ); +} + +#[test] fn function_call() { check_number( r#" diff --git a/crates/hir-ty/src/infer/mutability.rs b/crates/hir-ty/src/infer/mutability.rs index 8e3d71788f..784725da93 100644 --- a/crates/hir-ty/src/infer/mutability.rs +++ b/crates/hir-ty/src/infer/mutability.rs @@ -95,6 +95,21 @@ impl<'a> InferenceContext<'a> { self.infer_mut_not_expr_iter(fields.iter().map(|x| x.expr).chain(*spread)) } &Expr::Index { base, index } => { + if let Some((f, _)) = self.result.method_resolutions.get_mut(&tgt_expr) { + if mutability == Mutability::Mut { + if let Some(index_trait) = self + .db + .lang_item(self.table.trait_env.krate, LangItem::IndexMut) + .and_then(|l| l.as_trait()) + { + if let Some(index_fn) = + self.db.trait_data(index_trait).method_by_name(&name![index_mut]) + { + *f = index_fn; + } + } + } + } self.infer_mut_expr(base, mutability); self.infer_mut_expr(index, Mutability::Not); } diff --git a/crates/hir-ty/src/mir/lower/as_place.rs b/crates/hir-ty/src/mir/lower/as_place.rs index c6f4f66ada..425904850b 100644 --- a/crates/hir-ty/src/mir/lower/as_place.rs +++ b/crates/hir-ty/src/mir/lower/as_place.rs @@ -1,6 +1,7 @@ //! MIR lowering for places use super::*; +use hir_def::FunctionId; use hir_expand::name; macro_rules! not_supported { @@ -193,7 +194,24 @@ impl MirLowerCtx<'_> { if index_ty != TyBuilder::usize() || !matches!(base_ty.kind(Interner), TyKind::Array(..) | TyKind::Slice(..)) { - not_supported!("overloaded index"); + let Some(index_fn) = self.infer.method_resolution(expr_id) else { + return Err(MirLowerError::UnresolvedMethod); + }; + let Some((base_place, current)) = self.lower_expr_as_place(current, *base, true)? else { + return Ok(None); + }; + let Some((index_operand, current)) = self.lower_expr_to_some_operand(*index, current)? else { + return Ok(None); + }; + return self.lower_overloaded_index( + current, + base_place, + self.expr_ty_after_adjustments(*base), + self.expr_ty(expr_id), + index_operand, + expr_id.into(), + index_fn, + ); } let Some((mut p_base, current)) = self.lower_expr_as_place(current, *base, true)? else { @@ -210,6 +228,49 @@ impl MirLowerCtx<'_> { } } + fn lower_overloaded_index( + &mut self, + current: BasicBlockId, + place: Place, + base_ty: Ty, + result_ty: Ty, + index_operand: Operand, + span: MirSpan, + index_fn: (FunctionId, Substitution), + ) -> Result<Option<(Place, BasicBlockId)>> { + let is_mutable = 'b: { + if let Some(index_mut_trait) = self.resolve_lang_item(LangItem::IndexMut)?.as_trait() { + if let Some(index_mut_fn) = + self.db.trait_data(index_mut_trait).method_by_name(&name![index_mut]) + { + break 'b index_mut_fn == index_fn.0; + } + } + false + }; + let (mutability, borrow_kind) = match is_mutable { + true => (Mutability::Mut, BorrowKind::Mut { allow_two_phase_borrow: false }), + false => (Mutability::Not, BorrowKind::Shared), + }; + let base_ref = TyKind::Ref(mutability, static_lifetime(), base_ty).intern(Interner); + let result_ref = TyKind::Ref(mutability, static_lifetime(), result_ty).intern(Interner); + let ref_place: Place = self.temp(base_ref)?.into(); + self.push_assignment(current, ref_place.clone(), Rvalue::Ref(borrow_kind, place), span); + let mut result: Place = self.temp(result_ref)?.into(); + let index_fn_op = Operand::const_zst( + TyKind::FnDef( + self.db.intern_callable_def(CallableDefId::FunctionId(index_fn.0)).into(), + index_fn.1, + ) + .intern(Interner), + ); + let Some(current) = self.lower_call(index_fn_op, vec![Operand::Copy(ref_place), index_operand], result.clone(), current, false)? else { + return Ok(None); + }; + result.projection.push(ProjectionElem::Deref); + Ok(Some((result, current))) + } + fn lower_overloaded_deref( &mut self, current: BasicBlockId, diff --git a/crates/ide-diagnostics/src/handlers/mutability_errors.rs b/crates/ide-diagnostics/src/handlers/mutability_errors.rs index 83c61f73db..17a70f5701 100644 --- a/crates/ide-diagnostics/src/handlers/mutability_errors.rs +++ b/crates/ide-diagnostics/src/handlers/mutability_errors.rs @@ -565,6 +565,54 @@ fn f(x: [(i32, u8); 10]) { } #[test] + fn overloaded_index() { + check_diagnostics( + r#" +//- minicore: index +use core::ops::{Index, IndexMut}; + +struct Foo; +impl Index<usize> for Foo { + type Output = (i32, u8); + fn index(&self, index: usize) -> &(i32, u8) { + &(5, 2) + } +} +impl IndexMut<usize> for Foo { + fn index_mut(&mut self, index: usize) -> &mut (i32, u8) { + &mut (5, 2) + } +} +fn f() { + let mut x = Foo; + //^^^^^ 💡 weak: variable does not need to be mutable + let y = &x[2]; + let x = Foo; + let y = &mut x[2]; + //^^^^ 💡 error: cannot mutate immutable variable `x` + let mut x = &mut Foo; + //^^^^^ 💡 weak: variable does not need to be mutable + let y: &mut (i32, u8) = &mut x[2]; + let x = Foo; + let ref mut y = x[7]; + //^^^^ 💡 error: cannot mutate immutable variable `x` + let (ref mut y, _) = x[3]; + //^^^^ 💡 error: cannot mutate immutable variable `x` + match x[10] { + //^^^^^ 💡 error: cannot mutate immutable variable `x` + (ref y, _) => (), + (_, ref mut y) => (), + } + let mut x = Foo; + let mut i = 5; + //^^^^^ 💡 weak: variable does not need to be mutable + let y = &mut x[i]; +} +"#, + ); + } + + #[test] fn overloaded_deref() { check_diagnostics( r#" |